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Crop simulations

Jiangang Liu, Guangyao Wang, Qingquan Chu, Fu Chen
BACKGROUND: The nitrogen significantly increases the maize yield; however, the unreasonable use of nitrogen is common in China. An analysis of crop yield gaps can reveal the limiting factors for yield improvement; however, there's a lack of practical strategies for narrowing the yield gaps of household farms. The objectives of this study were to assess the yield gap of summer maize using an integrative method and to develop strategies for narrowing the maize yield gap through precise nitrogen fertilization...
October 17, 2016: Journal of the Science of Food and Agriculture
Ricardo Siqueira da Silva, Lalit Kumar, Farzin Shabani, Ezio Marques da Silva, Tarcisio Visintin da Silva Galdino, Marcelo Coutinho Picanço
Seasonal variations are important components in understanding the ecology of insect population of crops. Ecological studies through modeling may be a useful tool for enhancing knowledge of seasonal patterns of insects on field crops as well as seasonal patterns of favorable climatic conditions for species. Recently CLIMEX, a semi-mechanistic niche model, was upgraded and enhanced to consider spatio-temporal dynamics of climate suitability through time. In this study, attempts were made to determine monthly variations of climate suitability for Neoleucinodes elegantalis (Guenée) (Lepidoptera: Crambidae) in five commercial tomato crop localities through the latest version of CLIMEX...
October 13, 2016: International Journal of Biometeorology
Mukesh Dev Bhattarai, Silvia Secchi, Justin Schoof
Land-based carbon sequestration constitutes a major low cost and immediately viable option in climate change mitigation. Using downscaled data from eight atmosphere-ocean general circulation models for a simulation period between 2015 and 2099, we examine the carbon sequestration potential of alternative agricultural land uses in an intensively farmed Corn Belt watershed and the impact of climate change on crop yields. Our results show that switching from conventional tillage continuous corn to no-till corn-soybean can sequester the equivalent of 192...
October 11, 2016: Environmental Management
Hung K Doan, Karina Perez, Richard M Davis, David C Slaughter
From 2009 to 2011, freshly harvested processing tomatoes from California commercial fields were surveyed for mold species present in the mature fruit. Molds were recovered from the majority of fruit that had visual symptoms of black mold and other decays and from about a quarter of randomly sampled, asymptomatic fruit. Alternaria, Fusarium, and Geotrichum spp. were the most commonly recovered fungi in both symptomatic and random samples. Based on pairwise statistical analysis, the frequencies of 2 different fungal genera in a composite 11 kg-sample were, in general, statistically independent events, with the exception of a weak association between the incidence of Geotrichum with Alternaria, Cladosporium, or Stemphylium...
October 6, 2016: Journal of Food Science
F van den Berg, N D Paveley, F van den Bosch
Two key decisions that need to be taken about a fungicide treatment programme are (i) the number of applications that should be used per crop growing season, and (ii) the dosage that should be used in each application. There are two opposing considerations, with control efficacy improved by a higher number of applications and higher dose, and resistance management improved by a lower number of applications and lower dose. Resistance management aims to prolong the effective life of the fungicide, defined as the time between its introduction onto the market for use on the target pathogen, and the moment when effective control is lost due to a build-up of fungicide resistance...
October 2016: Plant Pathology
Balwinder-Singh, E Humphreys, D S Gaydon, P L Eberbach
Machinery for sowing wheat directly into rice residues has become more common in the rice-wheat systems of the north-west Indo-Gangetic Plains of South Asia, with increasing numbers of farmers now potentially able to access the benefits of residue retention. However, surface residue retention affects soil water and temperature dynamics, thus the optimum sowing date and irrigation management for a mulched crop may vary from those of a traditional non-mulched crop. Furthermore, the effects of sowing date and irrigation management are likely to vary with soil type and seasonal conditions...
October 2016: Field Crops Research
William Jokela, Jessica Sherman, Jason Cavadini
Manure applied to cropland is a source of phosphorus (P) and nitrogen (N) in surface runoff and can contribute to impairment of surface waters. Tillage immediately after application incorporates manure into the soil, which may reduce nutrient loss in runoff as well as N loss via NH volatilization. However, tillage also incorporates crop residue, which reduces surface cover and may increase erosion potential. We applied liquid dairy manure in a silage corn ( L.)-cereal rye ( L.) cover crop system in late October using methods designed to incorporate manure with minimal soil and residue disturbance...
September 2016: Journal of Environmental Quality
Richard Gaillard, Benjamin D Duval, William R Osterholz, Christopher J Kucharik
Soil texture is known to have an influence on the physical and biological processes that produce NO emissions in agricultural fields, yet comparisons across soil textural types are limited by considerations of time and practicality. We used the DayCent biogeochemical model to assess the effects of soil texture on NO emissions from agriculturally productive soils from four counties in Wisconsin. We validated the DayCent model using field data from 2 yr of a long-term (approximately 20-yr) cropping systems trial and then simulated yield and NO emissions from continuous corn ( L...
September 2016: Journal of Environmental Quality
Herbert Ssegane, M Cristina Negri
Locating bioenergy crops on strategically selected subfield areas of marginal interest for commodity agriculture can increase environmental sustainability. Location and choice of bioenergy crops should improve environmental benefits with minimal disruption of current food production systems. We identified subfield soils of a tile-drained agricultural watershed as marginal if they had areas of low crop productivity index (CPI), were susceptible to nitrate-nitrogen (NO-N) leaching, or were susceptible to at least two other forms of environmental degradation (marginal areas)...
September 2016: Journal of Environmental Quality
Laura Plieschke, Christian Edel, Eduardo C G Pimentel, Reiner Emmerling, Jörn Bennewitz, Kay-Uwe Götz
BACKGROUND: Extending the reference set for genomic predictions in dairy cattle by adding large numbers of cows with genotypes and phenotypes has been proposed as a means to increase reliability of selection decisions for candidates. METHODS: In this study, we explored the potential of increasing the reliability of breeding values of young selection candidates by genotyping a fixed number of first-crop daughters of each sire from one or two generations in a balanced and regular system of genotyping...
September 28, 2016: Genetics, Selection, Evolution: GSE
Emma Li Johansson, Marianela Fader, Jonathan W Seaquist, Kimberly A Nicholas
In the last decade, more than 22 million ha of land have been contracted to large-scale land acquisitions in Africa, leading to increased pressures, competition, and conflicts over freshwater resources. Currently, 3% of contracted land is in production, for which we model site-specific water demands to indicate where freshwater appropriation might pose high socioenvironmental challenges. We use the dynamic global vegetation model Lund-Potsdam-Jena managed Land to simulate green (precipitation stored in soils and consumed by plants through evapotranspiration) and blue (extracted from rivers, lakes, aquifers, and dams) water demand and crop yields for seven irrigation scenarios, and compare these data with two baseline scenarios of staple crops representing previous water demand...
October 11, 2016: Proceedings of the National Academy of Sciences of the United States of America
Luciana L Porfirio, David Newth, Ian N Harman, John J Finnigan, Yiyong Cai
We study changes in crop cover under future climate and socio-economic projections. This study is not only organised around the global and regional adaptation or vulnerability to climate change but also includes the influence of projected changes in socio-economic, technological and biophysical drivers, especially regional gross domestic product. The climatic data are obtained from simulations of RCP4.5 and 8.5 by four global circulation models/earth system models from 2000 to 2100. We use Random Forest, an empirical statistical model, to project the future crop cover...
September 23, 2016: Ambio
Yuanyuan Li, David Heckmann, Martin J Lercher, Veronica G Maurino
To feed a world population projected to reach 9 billion people by 2050, the productivity of major crops must be increased by at least 50%. One potential route to boost the productivity of cereals is to equip them genetically with the 'supercharged' C4 type of photosynthesis; however, the necessary genetic modifications are not sufficiently understood for the corresponding genetic engineering programme. In this opinion paper, we discuss a strategy to solve this problem by developing a new paradigm for plant breeding...
September 22, 2016: Journal of Experimental Botany
N Beaudoin, N Gallois, P Viennot, C Le Bas, T Puech, C Schott, S Buis, B Mary
The EU directive has addressed ambitious targets concerning the quality of water bodies. Predicting water quality as affected by land use and management requires using dynamic agro-hydrogeological models. In this study, an agronomic model (STICS) and a hydrogeological model (MODCOU) have been associated in order to simulate nitrogen fluxes in the Seine-Normandie Basin, which is affected by nitrate pollution of groundwater due to intensive farming systems. This modeling platform was used to predict and understand the spatial and temporal evolution of water quality over the 1971-2013 period...
September 22, 2016: Environmental Science and Pollution Research International
Xiaoying Liang, Hai Chen, Yanni Wang, Shixiong Song
The belief-desire-intention (BDI) model has been widely used to construct reasoning systems for complex tasks in dynamic environments. We have designed a capabilities and abilities (CA)-BDI farmer decision-making model, which is an extension of the BDI architecture and includes internal representations for farmer household Capabilities and Abilities. This model is used to explore farmer learning mechanisms and to simulate the bounded rational decisions made by farmer households. Our case study focuses on the Gaoqu Commune of Mizhi County, Shaanxi Province, China, where scallion is one of the main cash crops...
2016: SpringerPlus
Carl Stenoien, Kelly R Nail, Jacinta M Zalucki, Hazel Parry, Karen S Oberhauser, Myron P Zalucki
We review the postulated threatening processes that may have affected the decline in the eastern population of the monarch butterfly, Danaus plexippus L. (Lepidoptera: Nymphalidae), in North America. Although there are likely multiple contributing factors, such as climate and resource-related effects on breeding, migrating, and overwintering populations, the key landscape level change appears to be associated with the widespread use of genetically modified herbicide resistant crops that have rapidly come to dominate the extensive core summer breeding range...
September 21, 2016: Insect Science
Shu Wang, Hui Zheng, Shuhua Liu, Yucong Miao, Jing Li
The wheat production in midland China is under serious threat by frequent Dry-Hot Wind (DHW) episodes with high temperature, low moisture and specific wind as well as intensive heat transfer and evapotranspiration. The numerical simulations of these episodes are important for monitoring grain yield and estimating agricultural water demand. However, uncertainties still remain despite that enormous experiments and modeling studies have been conducted concerning this issue, due to either inaccurate synoptic situation derived from mesoscale weather models or unrealistic parameterizations of stomatal physiology in land surface models...
2016: PloS One
T A M Pugh, C Müller, J Elliott, D Deryng, C Folberth, S Olin, E Schmid, A Arneth
Climate change could pose a major challenge to efforts towards strongly increase food production over the coming decades. However, model simulations of future climate-impacts on crop yields differ substantially in the magnitude and even direction of the projected change. Combining observations of current maximum-attainable yield with climate analogues, we provide a complementary method of assessing the effect of climate change on crop yields. Strong reductions in attainable yields of major cereal crops are found across a large fraction of current cropland by 2050...
2016: Nature Communications
Benjamin Sultan, Marco Gaetani
West Africa is known to be particularly vulnerable to climate change due to high climate variability, high reliance on rain-fed agriculture, and limited economic and institutional capacity to respond to climate variability and change. In this context, better knowledge of how climate will change in West Africa and how such changes will impact crop productivity is crucial to inform policies that may counteract the adverse effects. This review paper provides a comprehensive overview of climate change impacts on agriculture in West Africa based on the recent scientific literature...
2016: Frontiers in Plant Science
Xiuwei Liu, Hongyong Sun, Til Feike, Xiying Zhang, Liwei Shao, Suying Chen
The major wheat production region of China the North China Plain (NCP) is seriously affected by air pollution. In this study, yield of winter wheat (Triticum aestivum L.) was analyzed with respect to the potential impact of air pollution index under conditions of optimal crop management in the NCP from 2001 to 2012. Results showed that air pollution was especially serious at the early phase of winter wheat growth significantly influencing various weather factors. However, no significant correlations were found between final grain yield and the weather factors during the early growth phase...
2016: PloS One
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